Re: [PATCH v3 2/4] log: add a --no-graph option

[Alex Henrie <alexhenrie24@gmail.com>]

On Fri, Feb 11, 2022 at 12:02 PM Junio C Hamano <gitster@pobox.com> wrote:
>
> Alex Henrie <alexhenrie24@gmail.com> writes:
>
> > --- a/builtin/blame.c
> > +++ b/builtin/blame.c
> > @@ -934,6 +934,7 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
> >               parse_revision_opt(&revs, &ctx, options, blame_opt_usage);
> >       }
> >  parse_done:
> > +     revision_opts_finish(&revs);
>
> This ...
>
> > diff --git a/builtin/shortlog.c b/builtin/shortlog.c
> > index e7f7af5de3..228d782754 100644
> > --- a/builtin/shortlog.c
> > +++ b/builtin/shortlog.c
> > @@ -388,6 +388,7 @@ int cmd_shortlog(int argc, const char **argv, const char *prefix)
> >               parse_revision_opt(&rev, &ctx, options, shortlog_usage);
> >       }
> >  parse_done:
> > +     revision_opts_finish(&rev);
> >       argc = parse_options_end(&ctx);
> >
> >       if (nongit && argc > 1) {
>
> ... and this.  It is a bit scary that we have to make sure all the
> users of parse_revision_opt() users need to call this new helper.
> Didn't we recently gain new documentation to help novices write
> their first revision-traversal-API-using program?  Does it need to
> be updated for this change (I didn't check)?

I don't see any documentation on how to use parse_revision_opt
directly; I only see documentation on how to use setup_revisions,
whose interface did not change.

Another approach would be to make a parse_rev_options_step function
that wraps parse_options_step and does the final steps when
parse_options_step returns PARSE_OPT_DONE. Would that be better?

> > diff --git a/revision.c b/revision.c
> > index 816061f3d9..a39fd1c278 100644
> > --- a/revision.c
> > +++ b/revision.c
> > @@ -2424,10 +2424,11 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
> >               revs->pretty_given = 1;
> >               revs->abbrev_commit = 1;
> >       } else if (!strcmp(arg, "--graph")) {
> > -             revs->topo_order = 1;
> > -             revs->rewrite_parents = 1;
> >               graph_clear(revs->graph);
> >               revs->graph = graph_init(revs);
> > +     } else if (!strcmp(arg, "--no-graph")) {
> > +             graph_clear(revs->graph);
> > +             revs->graph = NULL;
> >       } else if (!strcmp(arg, "--encode-email-headers")) {
> >               revs->encode_email_headers = 1;
> >       } else if (!strcmp(arg, "--no-encode-email-headers")) {
> > @@ -2524,8 +2525,6 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
> >                       unkv[(*unkc)++] = arg;
> >               return opts;
> >       }
> > -     if (revs->graph && revs->track_linear)
> > -             die(_("options '%s' and '%s' cannot be used together"), "--show-linear-break", "--graph");
> >
> >       return 1;
> >  }
>
> As a later "--no" can clear an earlier "--graph", we cannot
> incrementally check if options are compatible, until the end, at
> which time we can be sure that "--graph" is being asked.

Exactly. This is intentional, to avoid erroring out unnecessarily.

-Alex